package com.heima.kafka.sample;

import org.apache.kafka.clients.consumer.ConsumerConfig;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.apache.kafka.clients.consumer.ConsumerRecords;
import org.apache.kafka.clients.consumer.KafkaConsumer;

import java.time.Duration;
import java.util.Collections;
import java.util.Properties;

/**
 * 消费者
 */
public class ConsumerQuickStart {
    public static void main(String[] args) {
        //1.添加kafka配置
        Properties properties = new Properties();
        //kafka连接地址
        properties.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, "47.97.188.241:9092");
        //消费者组
        properties.put(ConsumerConfig.GROUP_ID_CONFIG, "group2");
        //手动提交偏移量
        properties.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, false);
        //消息的反序列化器
        properties.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringDeserializer");
        properties.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringDeserializer");
        //2.消费者对象
        KafkaConsumer<String, String> consumer = new KafkaConsumer<>(properties);
        //3订阅主题
        consumer.subscribe(Collections.singleton("itcast-topic-out"));
     /*   //让线程一直处于监听状态
        while (true) {
            //4.获取消息
            ConsumerRecords<String, String> consumerRecords = consumer.poll(Duration.ofMillis(1000));
            for (ConsumerRecord<String, String> consumerRecord : consumerRecords) {
                System.out.println(consumerRecord.key());
                System.out.println(consumerRecord.value());
                try {
                    //提交当前最新的偏移量
                    consumer.commitSync();
                } catch (Exception e) {
                    System.out.println("记录提交失败的异常" + e);
                }
            }

            //异步提交偏移量
            consumer.commitAsync((offsets, exception) -> System.out.println("记录错误的提交偏移量:" + offsets + ",异常信息" + e));
        }*/
        //同步和异步提交结合
        try {
            while (true) {
                //4.获取消息
                ConsumerRecords<String, String> consumerRecords = consumer.poll(Duration.ofMillis(1000));
                for (ConsumerRecord<String, String> consumerRecord : consumerRecords) {
                    System.out.println(consumerRecord.key());
                    System.out.println(consumerRecord.value());
                }
                consumer.commitAsync();
            }
        } catch(Exception e) {
            e.printStackTrace();
            System.out.println("记录错误消息" + e);
        } finally {
            try {
                consumer.commitSync();
            } catch (Exception e) {
                consumer.close();
            }
        }
    }
}
